Vacuum cleaners

ABSTRACT

The disclosure is directed to a vacuum cleaner in which an exhauster produces a flow of dust-laden air through fabric dust bags to separate dust from the air. Collected dust is shaken from the bags by valves for alternately reversing the direction of air flow and the dust falls by gravity into at least one throwaway plastic bag in a detachable receptacle underlying the filter bags. In the preferred embodiment, the receptacle is divided into separate compartments by spaced partition walls which, together with slots in the peripheral wall of the receptacle, permit the upper edges of the bags to be folded over the top of the partition walls and tucked downwardly therebetween. A pipe line connects the exhauster to the space between the plastic bags and receptacle walls to snap the bags to a fully open position and hold them open at all times while the exhauster is in operation. In another embodiment, the receptacle is adapted to receive a single plastic bag so as to snap it open as soon as the exhauster is initiated.

United States Patent Lee et al.

1451 Apr. 4, 1972 [54] VACUUM CLEANERS [72] Inventors: Wilfned J. Lee, East Syracuse; Robert H.

Arnold, Clay, both of NY.

52 US. Cl. ..55/302, 15/327 R, 15 347, 53/22, 55/337, 55/341, 55/357, 55/358, 55/366,

51 Int. Cl ..B0ld 46/04 [58] Field of Search ,.55/302, 428, 429, 395, 366, 55/341, 337, 374, 378-, 220/63 R, 65, 1 T; 15/327 Beth ..55/302 X White ..55/366 FOREIGN PATENTS OR APPLICATIONS 934,293 8/1963 Great Britain ..55/337 Primary ExaminerDennis E. Talbert, .lr.

Assistant Examiner-Vincent Gifford Attorney-Curtis, Morris & Safford ABSTRACT The disclosure is directed to a vacuum cleaner in which an exhauster produces a flow of dust-laden air through fabric dust bags to separate dust from the air. Collected dust is shaken from the bags by valves for alternately reversing the direction of air flow and the dust falls by gravity into at least one throwaway plastic bag in a detachable receptacle underlying the filter bags. In the preferred embodiment, the receptacle is divided into separate compartments by spaced partition walls which, together with slots in the peripheral wall of the receptacle, permit the upper edges of the bags to be folded over the top of the partition walls and tucked downwardly there- E QP-EL P e n onne slhes hay 3Q the space between the plastic bags and receptacle walls to snap the bags to a fully open position and hold them open at all times while the exhauster is in operation. In another embodiment, the receptacle is adapted to receive a single plastic bag so as to snap it open as soon as the exhauster is initiated.

7 Claims, 6 Drawing Figures P'ATENTEDAPR 4 I972 3. 653, 1 90 SHEET 2 BF 3 2/ 4 iv 62 22 3a INVI'LVIOHS WILFRED J. LEE ROBERT H. ARNOLD PATENTEDAPR 4 1972 SHEET 3 BF 3 INK'I'JQ'IOHS WILFRED J. LEE ROBERT H. ARNOLD ATTORNEYS VACUUM CLEANERS The present invention relates to vacuum cleaners and more particularly to improvements in vacuum cleaners of the type having a disposable bag or bags in which dust is collected.

Vacuum cleaners using disposable throwaway bags have been in common use for a considerable period of time. In one commonly used type, the disposable bag is inserted into a chamber of a tank-type vacuum cleaner and the bag itself acts as a filter for separating dust from air. When the bag becomes full, it is removed and thrown away, and a new empty bag is reinserted.

Larger commercial type vacuum cleaners also have been provided with filters therein in the form of fabric bags or sleeves. Each of a plurality of such fabric sleeves is attached at one end to a nipple on a septum plate which divides the tank into inlet and outlet chambers, and the opposite end of each sleeve is supported by a wall chamber into which it extends. Dusbladen air is directed into the inlet chamber and the outlet chamber is connected to an exhauster to cause air to flow through the fabric bags and filter out dust. A receptacle underlies the inlet chamber and from time to time the fabric bags are shaken, either automatically or manually, to cause the filtered dust to fall from the fabric bags into the receptacle by gravity. In some constructions, the fabric filter bags are shaken by reversing the direction of air flow therethrough, as by rapidly subjecting the outlet chamber, alternately, to a partial vacuum and atmospheric pressure. When the receptacle becomes full, it is detached and wheeled away to a place where the collected dust may be dumped.

It also has been proposed to use a disposable plastic bag in the receptacle of such vacuum cleaners so that only the plastic bag with the dust therein need be removed. These proposals have not been very successful, because of the large size and weight of these bags when full, and also because of the lack of control of such bags in the receptacle during a cleaning operation. For example, no suitable way has been found to hold the bags open, and the atmospheric pressure acting on the outside of the bag during operation tends to collapse the bag. When the filter bags are shaken by reversing the direction of airflow, the dust-receiving bags also tend to collapse and expand alternately, which presents more of a problem than removing the collected dust directly from the receptacle.

One of the objects of the present invention is to provide an improved construction in a tank-type vacuum cleaner which will snap a disposable plastic bag to a fully open position upon initiating operation of the exhauster and maintain it in a fully open position while the exhauster is operating.

Another object is to provide a vacuum cleaner of the type indicated in which fabric filter bags may be shaken by subjecting them alternately to a partial vacuum and atmospheric pressure without affecting the open position of a disposable plastic bag in its dust-receiving receptacle.

Still another object is to provide a vacuum cleaner of the type indicated which is of relatively simple and compact construction to adapt it for economical manufacture, and one which is reliable in operation.

These and other objects will become more apparent from the following description and drawings in which like reference characters denote like parts throughout the several views. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not a definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawings:

FIG. 1 is a side view of a commercial type vacuum cleaner incorporating the novel features of the present invention;

FIG. 2 is an enlarged side elevational view of the vacuum cleaner, partly in section, and showing disposable plastic bags in separate compartments of the dust-receiving receptacle and an arrangement for maintaining a partial vacuum between the plastic bags and walls of the compartments for all operating conditions;

FIG. 3 is a front elevational view of the vacuum cleaner and showing the slots in the peripheral wall of the lower tank section constituting a dust-collecting receptacle to permit the upper edges of the disposable plastic bags to be folded over the top edges of the receptacle;

FIG. 4 is a top plan view of the lower tank section constituting a dust-receiving receptacle and showing the spaced partition walls forming separate compartments for plastic bags and providing a space into which the top edges of the bags may be folded;

FIG. 5 is a view similar to FIG. 2 showing a receptacle of modified construction for use with a single plastic bag in accordance with the present invention; and

FIG. 6 is a sectional plan view taken on line 66 of FIG. 5 to show the receptacle and disposable plastic bag therein and showing the relationship of the parts.

The present invention is directed to an improved construction in a conventional vacuum cleaning system comprising a tank having an upper dust-separating section and a lower detachable section constituting a dust receptacle. In accordance with the present invention, the lower dust-receiving section is constructed to receive a disposable plastic bag to facilitate its easy removal from the receptacle when filled with dust. In one embodiment of the invention, the lower dustreceiving section is divided into separate compartments to receive a plurality of the disposable plastic bags. The partition walls forming the compartments are spaced apart between adjacent compartments, and the peripheral wall of the receptacle between the partition wall is slotted so that the top edges of the plastic bags may be folded over the top edges of the receptacle around their entire peripheries. The spaces between the walls of the compartments and the plastic bags are connected to an exhauster so that when the exhauster is initiated the difference in pressure will snap the bags to open position in the receptacle. Valve mechanism is provided for alternately subjecting fabric filter bags in the upper section to a partial vacuum and atmospheric pressure to shake the bags and cause dust to fall by gravity into the disposable plastic bags. In addition, the valve mechanism is so arranged as to maintain a partial vacuum between each plastic bag and its compartment walls when the dust separating section is opened to theatmosphere during the shaking operation. In another embodiment, the receptacle is constructed to receive a single plastic bag so as to cause it to snap open when operation of the exhauster is initiated.

Referring now to the drawings, FIG. 1 illustrates a commercial type vacuum cleaner 1 having a frame 2 with a pair of side wheels 3 adjacent the rear and a single wheel 3a at the front to adapt it to be moved to various locations. To this end, the front wheel 3a is a swiveling caster 4 having a handle 5 projecting forwardly therefrom. Mounted on the frame 2 is a tank 6 having an upper dust-separating section 7 rigidly affixed thereto and a lower detachable section 8 constituting a dustcollecting receptacle. A hose 9 has its inner end attach d'to the upper section 7 of the tank 6 and a vacuum cleaning tool 10 at its outer free end. The upper section 7 of the tank 6 also is connected by a bag cleaner valve 11 to an exhauster 12. Bag cleaner valve 11 comprises a T fitting having a branch 13 connected to the atmosphere and valves 14 and 15 at the lower end of the T and branch, respectively, see FIG. 2, which are adapted to be moved to opposite open and closed positions simultaneously by a linkage 16 having a handle 16a. In other words, when the valve 14 is open, the valve 15 to the atmosphere is closed so that the exhauster 12 will draw air through the vacuum cleaning tool 10, hose 9, tank 6 and pipe 11; but when the valve linkage 16 is operated to open the valve 15 in the branch 13 of the T to the atmosphere, the valve 14 to the exhauster is closed. As illustrated most clearly in FIG. 2, the exhauster 12 is driven by an electric motor 17 through suitable belts 18.

Tank 6 is illustrated as having a cylindrical shape, and the lower section 8 constituting the dust receptacle, has a peripheral wall 19, a bottom wall 20 with depending wheels 21 and a handle 27 to adapt it to be moved about in the manner of a cart. Lower section 8 may be lifted into or lowered out of engagement with the lower open end of the upper section 7 by an elevating platform 22 positioned between the spaced wheels 21 and underlying the bottom wall 20 of the section central thereof. The elevator platform 22 is pivoted to the frame at its opposite end and is raised and lowered by a manually actuated shaft 23 journaled in the frame and rotated by a handle 24. An eccentric disc 25 fast on the shaft 23 is connected through an adjustable rod 26 to the pivoted platform 22 intermediate its ends. Thus, by operating the handle 24, platform 22 may be raised to lift the peripheral wall 19 of lower section 8 into alignment and sealing engagement with the lower end of the peripheral wall of the upper tank section 7.

The upper section 7 of the tank has a septum plate 28, see FIG. 2, dividing the tank into an inlet chamber 29 to which hose 9 is connected, and an outlet chamber 30 connected through the bag cleaner valve 11 to exhauster 12. The septum plate 28 has a series of perforations 31 with nipples 32 surrounding the perforations. Fabric filter bags 33, of cylinder shape, have their lower open ends surrounding the nipples 32 and connected thereto by suitable fastening means 34 and their upper ends hooked onto supporting rings 35 on the top wall of the upper section 7 so that they will extend upwardly into the outlet chamber 30. Underlying the septum plate 28 is a conical guide chute 36 for directing dust from the inlet chamber 29 downwardly into the dust-receiving receptacle formed by the detachable lower section 8 of tank 6. Also, the tank 6 has a handhole and covering plate 37 for permitting access to the outlet chamber 30 in the tank.

As thus far described, the vacuum cleaner is of conventional construction and is operated by initiating the exhauster 12 which draws air and entrained dust through the tool and hose 9 into the inlet chamber 29 and then through the perforations 31 in the septum plate 28 and fabric filter bags 33 to the outlet chamber 30 and thence through the bag cleaner valve 11 to the exhauster. As the dust-laden air flows through the fabric dust bags, the dust is separated from the air and clings to the sides of the bag. From time to time, the linkage 16 is operated to reverse the direction of airflow through the fabric bags which shakes the dust from the bags. The released dust then falls by gravity through the guide-chute 36 into the receptacle constituting the lower detachable section 8 of the tank 6. When the receptacle becomes full, it is detached from the upper section 7 of the tank by turning the handle 24 and operating through the eccentric disc 25 and adjustable rod 26 lowers the platform 22. The receptacle is removed to a suitable location and the collected dust dumped therefrom.

In accordance with the present invention, a disposable plastic bag or bags are inserted in the receptacle and the latter is so connected to the exhauster as to snap the bag or bags to an open position as soon as operation of the exhauster is initiated and holds the plastic bags open at all times during operation of the exhauster. In the embodiment illustrated in FIGS. 1 to 4, the lower section 8 of the tank 6 constituting the dust receptacle is divided by partition walls into separate compartments 40, 41 and 42 as shown most clearly in FIG. 4. The partition walls 40A and 4013 for compartment 40 are spaced from the partition walls 41A and 42B of adjacent compartments 41 and 42 to provide a space therebetween. Similarly, the partitions 41A and 41B of compartment 41 are spaced from the partition wall 408 and 42A of compartment 42 in a similar manner. The compartments 40, 41 and 42 have the common bottom wall 20, and the bottom wall has perforations 44 between the spaced walls of adjacent compartments to permit atmospheric air, dirt or other materials to pass therethrough. Also, the peripheral wall 19 of the lower section 8 has slots 46, 46A and 46B in its upper edge between the spaced partition walls of adjacent compartments 40, 41 and 42.

As will be observed in FIG. 4, the bottom wall 20 has sectorial openings 47 at the axis of the peripheral wall 19 which communicate with each of the compartments 40, 41 and 42 at the apex between converging partition walls, respectively. Surrounding the openings 47 is an annular boss 48 projecting upwardly from a head 49 at the outer end of the elevating platform 22 for raising and lowering the lower section 8 and which engages the bottom wall of the section. Also, as shown most clearly in FIG. 2, a perforated false bottom 40C, 41C and 42C is provided in each compartment 40, 41 and 42 which is spaced from the bottom wall 20. With this construction a disposable bag 50 of a suitable flexible material, such as plastic, may be inserted in each of the compartments 40, 41 and 42.

Because of the spaced partition walls 40A and 42B, 40B and 41A and 41B and 42A, the upper end portion 51 of each of the bags 50 may be folded over the top of the partition and peripheral walls of the receptacle and tucked down in the space between adjacent walls. Also, slots 46, 46A and 468 permit the upper end portion 51 of the bag to be folded continuously around the corner formed by a partition wall, such as 40A, and the peripheral wall 19.

A skeleton frame 54 is provided in the lower open end of the upper section 7 of the tank 6 which has a peripheral rim 55, see FIG. 2, and radial arms 56 which form pads overlying the top of the spaced partition walls 40A and 42B, 40B and 41A, 41B and 42A of adjacent compartments and peripheral wall 20 and the edges of the plastic bags folded thereover to seal the joints therebetween. Thus, when the lower section 8 is raised into engagement with the skeleton frame 54 at the lower end of the upper section 7 of the tank, the two sections form a complete tank with a plastic bag 50 in each of the compartments 40, 41 and 42 with their folded over edges sealed between the sections.

The improvement also includes a connection 60 between the exhauster l2 and the sectorial openings 47 underlying the three compartments 40, 41 and 42. As shown, the connection includes the head 49 and annular boss 48 at the outer end of the elevating platform 22 which cooperates with the bottom of the receptacle 8 to seal the joint around the opening 47. The head 49 comprises a hollow suction box having a fixed pipe 62 extending therefrom and supported on the elevating platform 22. The opposite end of pipe 62 is connected by a flexible hose 63 to the lower end of the valve 14 of the bag cleaner valve complex 11 where it enters the exhauster 12. Thus, the connection 60 subjects the space between the plastic bags 50 and the partition wall and bottom wall of the compartments 40,41 and 42 to a partial vacuum. Immediately upon operation of the exhauster 12, the difference in pressure snaps the bags 50 to open position in the compartments,

It will further be observed by reference to FIG. 2 that the end of the flexible conduit 63 connected to the exhauster 12 is located below the valve 14 in the bag cleaner valve 11 so that whenever the bag-shaking linkage 16 is operated to submit the outlet chamber 30 of the tank to atmospheric pressure, the valve 14 will close ofi the bag cleaner valve complex 11 so that the partial vacuum will be maintained in the space between the bags 50 and walls of compartments 40, 41 and 42. One form of the invention having now been described, the mode of operation is next explained.

With the lower section 8 detached from the upper section 7 of the tank 6, a plastic bag 50 is inserted in each compartment 40, 41 and 42, and the upper edge portions 51 of the bags are folded over the top edges of the walls of the compartments 40, 41 and 42 previously explained. The lower section or receptacle 8 is then wheeled back into position to align its peripheral wall 19 with the peripheral wall of the upper section of the tank 6. Handle 24 is then operated to raise the elevating platform 22. The circular boss 48 on the head 49 at the outer end of the platform 22 first engages the bottom wall 20 of receptacle and surrounds the openings 47 therein to seal the joint therebetween and then lifts the receptacle until its upper edge engages the skeleton frame 54. The rim 5S and radial arm 56 of the skeleton frame 54 then overlie the spaced partition walls of adjacent compartments 40, 41 and 42 and seals the joint therebetween and between the folded over edges of the plastic bag around the entire periphery of each compartment.

Upon initiation of the exhauster 12, air flows from the space between the plastic bags 50 and the walls of the compartments 40, 41 and 42 to produce a partial vacuum in the space. This partial vacuum immediately draws the sides of the plastic bags against the walls of the compartments 40, 41 and 42 to snap the bags open and hold the bags in open position.

Dust-laden air is also drawn through the inlet chamber 29, filter bags 33, outlet chamber 30 and bag cleaner valve 11 to the exhauster 12. The fabric bags 33 separate the dust from the air and, from time to time, linkage 16 is operated to quickly reverse the direction of airflow and thereby shake the collected dust from the filter bags. The dislodged dust flows by gravity through the guide chute 36 into the plastic bags 50 in the receptacle 8. During such a bag-shaking operation, the valve 14 is always closed when the outlet chamber 30 in the upper section 7 of the tank is open to the atmosphere so that the exhauster 12 will maintain a partial vacuum in the space between the plastic bags and the compartments 40, 41 and 42 in which they are located.

When the plastic bags become filled with dirt, the operation of the exhauster 12 is stopped, the handle 24 operated to lower the elevating platform 22 until the wheels 21 of the receptacle constituting the lower section 8 of the tank are positioned on the floor. The receptacle then may be wheeled away to a location where the dirt is to be dumped. To this end, the top of the plastic bags 50 may be twisted to closed position, after which the bags may be lifted from the container. New bags 50 are then inserted into compartments 40, 41 and 42, the upper end portions 51 of the bags folded over the partition and peripheral walls of the compartments 40, 41 and 42 and tucked into the open space between adjacent partition walls, the receptacle returned to its position in alignment with the upper section 7 of tank 6, and the handle 24 again operated to lift the receptacle into engagement with the lower open end of the upper tank section in the manner previously described. Operation of the exhauster 12 then may be initiated to start another cleaning operation.

FIGS. 5 nd 6 illustrate a receptacle 8a of modified construction for use with a single disposable plastic bag 50a. In this modified construction, the receptacle 8a is generally similar to the receptacle 8 in FIGS. 1 to 4 and is raised to its elevated position by an elevator 22a in the same way as previously described. The elevator 22a has a head 49a at its outer end with an upstanding annular boss 48a for engaging the bottom wall 200 of the receptacle to seal the joint therebetween and the head is connected through a pipe 62a and flexible hose 63a to the exhauster 12a in the same way as the embodiment illustrated in FIGS. 1 to 4.

However, the receptacle 8a is not divided into separate compartments, but instead, comprises only the peripheral wall 190 and bottom wall 200 forming a single cylindrical compartment 40a. The peripheral wall 19a of the receptacle 8a has an outwardly directed flange 19b at its upper edge which underlies a peripheral rim 55a and compressible gasket 55b at the lower end of the upper section 7a of the tank 6a to seal the joint therebetween. The bottom wall a also has perforations 47a located centrally thereof within the perimeter of the upstanding boss 48a on the head 49a.

Mounted in the receptacle 8a is a basket 70 having a cylindrical side wall 71 of smaller diameter than the wall 19a of the receptacle 8a and a bottom wall 72 attached to the side wall above its lower edge to space the bottom wall above the bottom wall 20a of the receptacle. A flange 73 projects radially from the upper edge of the side wall 71 to engage the inside of the side wall 19a of the receptacle 8a to hold the basket centered therein. In addition, the bottom wall 72 of the basket has depending ribs 74 and 75 for providing additional support. Both the cylindrical side wall 71 and bottom wall 72 have perforations 76 and 77, respectively. A plastic bag 50a is placed in the basket 70 with its upper edge 50b folded outwardly over the upper edges of the basket and receptacle in the manner illustrated in FIG. 5 and sealed by engagement with the gasket 55b at the lower end of the upper tank section 7a. As shown in F IG. 6, receptacle 8a has a handle 27a similar to the handle 27 shown in FIG. 3.

With he construction illustrated in FIGS. 5 and 6 a partial vacuum is produced in the space 78 between the basket and receptacle upon initiation of the exhauster 12a to snap the plastic bag 50a to an open position and maintain it open so long as the exhauster remains in operation. When the plastic bag 50a becomes filled, the receptacle 8a lowered as previously explained, the full bag removed, another empty bag inserted, the receptacle raised into engagement with the upper section of tank section 7a and the exhauster 12a initiated to start a new cycle of operation as previously explained with respect to the embodiment of the invention illustrated in F IGS. 1 to 4.

It will now be observed that the present invention provides an improved construction in a vacuum cleaning system for snapping a disposable plastic bag to a fully open position upon initiation of the exhauster and maintain the bag in open position during a cleaning operation. It will further be observed that the present invention provides a vacuum cleaner having fabric filter bags which may be shaken by alternately reversing the direction of airflow through the bags, in rapid succession, without affecting the open position of the plastic bags in the receptacle. It will still further be observed that the present invention provides a vacuum cleaner which is of relatively simple and compact construction, economical to manufacture, and one which is reliable in operation.

While two embodiments of the invention are herein illustrated and described, it will be understood that further modifications may be made without departing from the spirit and scope of the invention. Therefore, without limitation in this respect, the invention is defined by the following claims.

We claim:

1. A vacuum cleaner having a tank divided into upper and lower chambers, a plurality of fabric filter bags mounted in said upper chamber and communicating with said lower chamber, a connection for delivery of dust-laden air to said lower chamber, an exhauster, a first pipe between said upper chamber and said exhauster to cause air to flow through said filter bags and separate dust from the air, closure valve means in said first pipe, vent valve means connected to said first pipe, valve operating means interconnecting said vent valve means and valve closure means and manipulable to vary the pressure in said upper chamber to shake said filter bags and cause dust to drop therethrough, said tank having a lower section detachable from the upper section thereof and communicating with said lower chamber and having a bottom and side walls, said detachable lower section being normally in sealing engagement with the upper tank section, a disposable bag of flexible material positioned in said detachable lower section with the upper peripheral edge of said disposable bag folded over the upper periphery of said detachable lower section, a second pipe disposed with an upturned end in operative contact with the bottom of said detachable lower section and interconnecting the space between said disposable bag and said detachable lower section with said first pipe at a point between said exhauster and said closure valve means whereby said disposable bag is held against the bottom and side walls of said detachable lower section during operation of said valve means to shake said filter bags, said upturned end of said second pipe being movably mounted for movement into and out of contact with the bottom of said detachable lower section.

2. A vacuum cleaner having a tank mounted on a frame and divided into upper and lower chambers, a plurality of fabric filter bags mounted in said upper chamber and communicating with said lower chamber, a connection for delivering dustladen air to said lower chamber, an exhauster, a connection between said upper chamber and said exhauster to cause air to flow through said filter bags and separate dust from the air, said tank having an upper section and a detachable lower section communicating with said lower chamber and normally sealed to the upper section of said tank, said detachable section having bottom and side walls, a disposable bag of flexible material in said lower section with its upper peripheral edge folded over the upper peripheral edge of said detachable lower section, means for shaking said filter bags to cause dust to fall therefrom into said disposable bag, an elevating platform positioned below said detachable lower tank section and adapted to raise the tank section into sealing engagement with the upper tank section, said platform being pivoted at one end to said tank frame and having its opposite end underlying the lower section of the tank and means for raising and lowering the platform comprising a shaft mounted for rotation in bearings in the tank frame, an eccentric disk on the shaft, and an eccentric follower connected to the disk and the platform.

3. A vacuum cleaner having a tank divided into upper and lower chambers, a plurality of fabric filter bags mounted in said upper chamber and communicating with said lower chamber, a connection for delivering dust-laden air to said lower chamber, an exhauster, a connection between said upper chamber and said exhauster to cause air to flow through said filter bags and separate dust from the air, said tank having an upper section, and a detachable lower section communicating with said lower chamber and having bottom and side walls, the upper and lower sections of said tank being normally in sealed engagement, partition walls dividing said lower section into a plurality of separate compartments, disposable bags of flexible material in said compartments, means for shaking said filter bags to cause dust to fall therefrom into said disposable bags and means interconnecting the spaces between said disposable bags and the walls of said compartments with said exhauster to hold said bags against the walls of said compartments.

4. A vacuum cleaner according to claim 3 wherein the partitioned walls of adjacent compartments are spaced from each other, the entire upper periphery of each disposable bag is folded over the upper perimeter of the walls of the companment in which the bag is disposed and a skeleton frame is interposed between the two tank sections, said skeleton frame having pads overlying the top of the partition walls and folded over edges of the disposable bags for sealing the joints therebetween.

5. A vacuum cleaner in accordance with claim 4 in which the lower section of the tank is cylindrical, the partition walls forming the separate compartments extend radially, the bottom wall of the lower tank section having an opening to each compartment adjacent the center of the section, and the means connecting the exhauster to the space between the lower section of the tank and disposable bags is a header underlying the bottom wall of the lower section of the'tank around the openings therein in open communication with the separate compartments between the radial partition walls.

6. A vacuum cleaner in accordance with claim 5 in which each compartment has a perforated bottom wall spaced from the bottom wall of the lower tank section to support the bottom of each flexible bag above the bottom wall of the lower tank section.

7. A vacuum cleaner in accordance with claim 6 in which the connection between the upper chamber and exhauster is a pipe, the means connecting the exhauster to the space between the lower section of the tank and the disposable bag is a continuation of the first mentioned pipe at the exhauster, and valve means in the first mentioned pipe for closing the connection between said tank chamber and exhauster and venting said chamber to the atmosphere whereby to maintain a partial vacuum between the lower section of the tank and disposable bag at all times while the exhauster is operating. 

1. A vacuum cleaner having a tank divided into upper and lower chambers, a plurality of fabric filter bags mounted in said upper chamber and communicating with said lower chamber, a connection for delivery of dust-laden air to said lower chamber, an exhauster, a first pipe between said upper chamber and said exhauster to cause air to flow through said filter bags and separate dust from the air, closure valve means in said first pipe, vent valve means connected to said first pipe, valve operating means interconnecting said vent valve means and valve closure means and manipulable to vary the pressure in said upper chamber to shake said filter bags and cause dust to drop therethrough, said tank having a lower section detachable from the upper section thereof and communicating with said lower chamber and having a bottom and side walls, said detachable lower section being normally in sealing engagement with the upper tank section, a disposable bag of flexible material positioned in said detachable lower section with the upper peripheral edge of said disposable bag folded over the upper periphery of said detachable lower section, a second pipe disposed with an upturned end in operative contact with the bottom of said detachable lower section and interconnecting the space between said disposable bag and said detachable lower section with said first pipe at a point between said exhauster and said closure valve means whereby said disposable bag is held against the bottom and side walls of said detachable lower section during operation of said valve means to shake said filter bags, said upturned end of said second pipe being movably mounted for movement into and out of contact with the bottom of said detachable lower section.
 2. A vacuum cleaner having a tank mounted on a frame and divided into upper and lower chambers, a plurality of fabric filter bags mounted in said upper chamber and communicating with said lower chamber, a connection for delivering dust-laden air to said lower chamber, an exhauster, a connection between said upper chamber and said exhauster to cause air to flow through said filter bags and separate dust from the air, said tank having an upper section and a detachable lower section communicating with said lower chamber and normally sealed to the upper section of said tank, said detachable section having bottom and side walls, a disposable bag of flexible material in said lower section with its upper peripheral edge folded over the upper peripheral edge of said detachable lower section, means for shaking said filter bags to cause dust to fall therefrom into said disposable bag, an elevating platform positioned below said detachable lower tank section and adapted to raise the tank section into sealing engagement with the upper tank section, said platform being pivoted at one end to said tank frame and having its opposite end underlying the lower section of the tank and means for raising and lowering the platform comprising a shaft mounted for rotation in bearings in the tank frame, an eccentric disk on the shaft, and an eccentric follower connected to the disk and the platform.
 3. A vacuum cleaner having a tank divided into upper and lower chambers, a plurality of fabric filter bags mounted in said upper chamber and communicating with said lower chamber, a connection for delivering dust-laden air to said lower chamber, an exhauster, a connection between said upper chamber and said exhauster to cause air to flow through said filter bags and separate dust from the air, said tank having an upper section, and a detachable lower section communicating with said lower chamber and having bottom and side walls, the upper and lower sections of said tank being normally in sealed engagement, partition walls dividing said lower section into a plurality of separate compartments, disposable bags of flexible material in said compartments, means for shaking said filter bags to cause dust to fall therefrom into said disposable bags and means interconnecting the spaces between said disposable bags and the walls of said compartments with said exhauster to hold said bags against the walls of said compartments.
 4. A vacuum cleaner according to claim 3 wherein the partitioned walls of adjacent compartments are spaced from each other, the entire upper periphery of each disposable bag is folded over the upper perimeter of the walls of the compartment in which the bag is disposed and a skeleton frame is interposed between the two tank sections, said skeleton frame having pads overlying the top of the partition walls and folded over edges of the disposable bags for sealing the joints therebetween.
 5. A vacuum cleaner in accordance with claim 4 in which the lower section of the tank is cylindrical, the partition walls forming the separate compartments extend radially, the bottom wall of the lower tank section having an opening to each compartment adjacent the center of the section, and the means connecting the exhauster to the space between the lower section of the tank and disposable bags is a header underlying the bottom wall of the lower section of the tank around the openings therein in open communication with the separate compartments between the radial partition walls.
 6. A vacuum cleaner in accordance with claim 5 in which each compartment has a perforated bottom wall spaced from the bottom wall of the lower tank section to support the bottom of each flexible bag above the bottom wall of the lower tank section.
 7. A vacuum cleaner in accordance with claim 6 in which the connection between the upper chamber and exhauster is a pipe, the means connecting the exhauster to the space between the lower section of the tank and the disposable bag is a continuation of the first mentioned pipe at the exhauster, and valve means in the first mentioned pipe for closing the connection between said tank chamber and exhauster and venting said chamber to the atmosphere whereby to maintain a partial vacuum between the lower section of the tank and disposable bag at all times while the exhauster is operating. 